What the viewers don't know is that this memorable show could have been canceled. Just two days before the taping, the patriarch of the Osmond family, Donny and Marie's father, George, passed away at the age of 90.

After hearing the news, Tara Montgomery, the lead producer on that show, says she waited for Donny to call and cancel their appearance. "Donny called me and said, 'Tara, we're all coming,'" she says. "They delayed the memorial service. They did not have a memorial service for their father because they were so committed to this show, all coming together and celebrating their family."

Arranging for 126 people to fly across the country was no easy task—but Tara says the Osmonds did it with a smile. "I've worked here 16 years," she says. "I've worked with every celebrity that you can think of, and there is no doubt in my mind, if anybody asks me in 30 years, 'Who was the nicest celebrity?' Donny Osmond and his family."

Senior field producer Melinda Morrison says she was amazed by how tight-knit this famous family was. "Donny and Marie knew all of their [family members'] names," she says. "They really are connected."